Trisecting an Angle Using the Conchoid of Nicomedes
Date: 08/16/2002 at 20:30:39 From: J. A. Greene Subject: Trisecting an angle and using a Nichomedian choncoid I attempted to trisect an angle using the Nichodemian Choncoid (which I constructed using a compass and straightedge), and I showed it to my dad, who said that it was 100% impossible to do so, and I showed it to my mom, who said that I might actually have trisected the angle. I want to know if it possible that I could have trisected it using the conchoid. JA Greene
Date: 08/16/2002 at 23:13:37 From: Doctor Peterson Subject: Re: Trisecting an angle and using a Nichomedian choncoid Hi, J. A. Of course it is possible! The Greeks invented this curve for the purpose of trisecting angles; it's nothing new. The problem is that it doesn't follow the rules for a compass and straightedge construction, which must use NOTHING else. That is what is impossible, not trisection using other tools. You didn't really construct the curve with compass and straightedge alone, since it is not composed only of lines and circles; you must have constructed some points and then drawn a curve through them somehow. See the Dr. Math FAQ: Impossible constructions http://mathforum.org/dr.math/faq/faq.impossible.construct.html and this article from the MacTutor History of Mathematics archive at St. Andrews University:: Trisecting an angle <http://www-gap.dcs.st-and.ac.uk/~history/HistTopics/ Trisecting_an_angle.html> And see this on the conchoid: Conchoid of Nicomedes - Xah Lee <http://www.xahlee.org/SpecialPlaneCurves_dir/ ConchoidOfNicomedes_dir/conchoidOfNicomedes.html> If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
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